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Transmission Trouble

Discussion in 'GM Powertrain' started by ErikD-WPE, Aug 15, 2009.

  1. ErikD-WPE

    ErikD-WPE New Member

    I have a 1997 GMC 1500, 2 wd with an automatic transmission. I just got it rebuilt about a week ago and the transmission is supposed to be good up to 500 horses, beast sunshell intalled, corvette servo, stronger clutches, boost valve, shift kit, TCI stall converter 2200 max stall . It drives excellent under cruising conditions, but when i get ready to race, ill put it in 1st gear, stall up and take off it just acts like its slipping and wont get above 3000 rpm and then ****s to 2nd gear and fine from there. If i leave it in 3rd and stall and leave, it seems a little sluggish out of 1st but goes all the way through the rpm band and shifts fine from there. also when im highway speed and i want to pass someone, it kicks down but it goes up and down in rpm, varying about 1000 rpm a few times and then will take off, any ideas on what is going on?
  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    The manual valve may be out of adjustment. Take it back in and have the shop look at it.
  3. ErikD-WPE

    ErikD-WPE New Member

    Can you explain how it is out of adjustment? I tried telling the guy who rebuilt it what was going on and my shift light on my console was not reading right and he said that might be causing my problems so i fixed it and its still doing it. I just want to understand how it works, so when i talk to him I can understand.
  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    The linkage inside the pan can be out of whack, a missing check ball, valve body gasket out of position, cross leak causing the band to drag, I could go on all night. The bottom line is if you continue to drive it like this you could burn up a band or a clutch pack. I don't understand why you paid good money to have your trans rebuilt and now you are trying to fix someone else's mistake? If I rebuilt your trans and it was doing this I would tell you to bring it back to me right away.
  5. ErikD-WPE

    ErikD-WPE New Member

    I see what your talking about. Yea, im going to talk to him monday about it. He has a shop in kentucky also and he goes back and forth between shops so its kind of hard to catch him. I just need a little info on what could be causing the problem, because he seems like he does not want to blame it on his work or want to fix it. Plenty of people said he was reputable, but im starting to get annoyed. Thanks for the info.
  6. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Tell him he's screwed now. "his" problem has become worldwide and we want him to fix it! :lol:
  7. ErikD-WPE

    ErikD-WPE New Member

    Better believe he will lol
  8. ErikD-WPE

    ErikD-WPE New Member

    So I took my truck in to him this morning so he could look at it. I guess he done a few checks on it and called his tech support guy, which is supposed to be amazingly smart with transmisssion diagonistics and they told him that from the factory, putting it in manual low 1st gear i should of never been able to get to 5000 rpm before it would shift to second and they dont see how im able to get it to 3000 rpm right now before shifting to second gear at a wide open throttle. So I asked him, how is it that all you done was just beef up my transmission and didnt really change anything computer wise, is it messing up now, should just be beefier not computer tune wise and he could not give me an answer and said thats the way it is and told me to come pick up my truck. so now i have to figure out why, myself, is it acting up. Any suggestions on where to start?
  9. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    The PCM will limit the RPM and control the shift points. What probably happened is the parts he installed is causing the transmission to stay in low longer than the programming and the engine is hitting the rev limiter. If your only problem is at high RPM a programmer or custom tune should fix it.
  10. ErikD-WPE

    ErikD-WPE New Member

    No my problem is at low rpm. I cant get above 3000 in manual 1st gear and i used to be able to get to 5300 rpm in manual 1st gear before the build. I have a laptop programmer for my truck so i can custom tune it how i want. Ive changed all my shift points and what not when i had the stock tranny in and ran well for awhile until it gave, now being rebuilt it is doing this to me.

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